Hollow-drill steel-punching machine.



T. DAVIES.

HOLLOW DRILL STEEL PUNCHING MACHINE.

APPLICATION FILED JULY22, 1916,

Patented July 3, 1917.

2 SHEETS-SHEET l- T. DAVIES.

HOLLOW DRILL STEEL PUNCHING MACHINE.

APPLICATION FILED JULY22. I916.

1 ,232,235 Patelitsi 31312 5212917.

Q .H|I|-|[||1-/%//// v o 0 Q O N) w a T ll \:R Z m 5k Q L 0 THOMASavies, on JEROME, ARIZONA.

HOLLOW-DRILL STEEL-PUNCHING MACHINE.

Specification of Letters Patent.

Patented July 3, 1917.

Application filed 31113722, 1916. v Serial No. 110,789.

To all whom it may concern:

Be itknown thatflI, THOMAS DAVIES, ,a citizen of the United States ofAmerica, residing at the ,cityof Jerome, county of Yavapai, and. Stateof Arizona, have invented anew and useful Hollow-Drill Steel- PunchingMachine, of which the following is a specification.

My invention relates to a new hollow drill steel punching machine; andthe objects of my invention are:

First, To providea machine for enlarging the axial aperture. of the.drill bit end of heated hollow drill. tool steel to enable the waterandiair passageway through thesteel to be kept open during therockcutting on the end of hollow drill steel, or during the resharpening ofdulled hollow steel drills.

Second, To provide means for keeping the hollow steel punching andenlarging pin cool.

Third, To provide means for automatically gripping and holding heated,hollow drill steel of different sizes in. axial alinement with the axialaperture enlarging pin.

:Fourth, To provide means for cushioning the reciprocating punchingstrokes of the punching pin;

Fifth, To provide means for remova-bly holding and for quickly changingused and worn punching pins for new ones. And

Sixth, Toprovide a simple, easily operated, thoroughly practical hollowsteel punching machine that will very materially reduce the cost ofresharpening hollow drill steel and that always enlarges and leaves theaxial aperture through the drill. steel open and to the sizedesiredafterthedrill bit at its end is formed and sharpened.

I attain these objects by the mechanism illustrated in the accompanyingdrawings, in which:

Figure 1, is a side elevation of the improved hollow steel punchingmachine, and showing a drill steel in position for the punchingoperation.

Fig. 2, is a vertical, longitudinal sectional view through the twocylinders and parts connected therewith, constituting th e punchingmechanism,the drill steel vise and its operating cylinder being omitted.

' Fig. 3, is an end view of the drill steel clamping vise.

Fig. 4, is a side view, partly broken away, of the pneumatic cylinderand piston, which operates the movable jaw of the vise.

the cutting point of drill bits and to the bottom of holes in rock asthey are drilled,

to allay the rock dust and force it from the holebeing drilled, hollowsteel is used in the form of bars varying in length from about a .footor two to about fifteen or more feet.

These bars of hollow steel are generally from three-quarters of an inchto an inch and a half in diameter, depending on the size of drillingengine used, and these bars as most generally used are round in crosssection and are known as round hollow drill steel, and each bar has anaxial aperture formed through it from end to end of from abouta quarterof an inch to about threeeighths of an inch in diameter, depending onthe size or diameter of the bar.

One end of each bar that is to be made into a rock cutting drill isarranged and adapted to be clamped in the chuck of the drilling engine;the opposite end is heated to a forging heat and is enlarged somewhatand a rock cutting bit that has several V- shaped rock cutting lips,four being most generally used, these rock cutting lips radiating in acircle from the center of the hollow'steel to the periphery of itsenlarged end portion, is forged on it. A view of such a hollow drill isshown in Figs. 1, 6, and 7.

In order that the function of my hollow steel punching machine may beclearly understood relative to the forming of rock cutting bits on oneend of new bars of hollow drill steel, and to the resharpening of drillsthat have been worn dull by use in drilling holes in rock, I will makethis explanation:

In large ore mining mines several hundred drills are worn dull every dayand have to be resharpened, and those that have been worn too short orbroken have to be replaced by new ones. It is necessary whenresharpening a drill or when forming a new one that the axial aperturein the end of the bit that the rock cutting lips are formed on be keptopen preferably to the full size or a trifle larger than the size of theaperture through the bar. These drills are sharpened in drill sharpeningmachines, of which there are a number in common use, and if something isnot used the hole will be wholly or partially closed, which would renderit inoperative for the use of dust laying fluid.

The commonest way of keeping the hole open is to drive a cold steel pininto the heated drill bit end of the steel just before it is subjectedto the lip forging and sharpening dies of the sharpening machine, andthen the sharpening action is completed to instantly withdraw the pin bydriving or pulling the pin out, and as the hot end of the drill cools,it shrinks on the cold pin and it requires force and time to drive orpull it out.

My present invention provides a machine in which the drills the instantthey are heated to a resharpening heat, can be quickly placed, grippedand'centered in axial alinement with the longitudinal axis of the drillbar, and the hole in its heated end be almost instantly enlarged to asize that will still leave it of the same or a trifle larger diam eterthan the hole through it and be released and discharged and placed in adrill sharpening machine without perceptibly losing its drill sharpeningheat.

Consequently reheating is not necessary, and the hole does not have tobe again touched after the drill is resharpened.

My machine automatically centers and automatically moves the pin toenlarge the hole in the drills, and its action is a punching pressureforce instead of a blow, in moving the enlarging pin into theend of thedrills, and my machine thus keeps the texture of the steel in a uniformcondition,

and it effects a saving of about fifty percent. in the time and laborrequired to resharpen a drill over the common method of driving a pininto the hole by hand and of then forcing it out by hand.

The detail description of the construction and operation of my inventionis as follows:

Referring to the drawings,-' Fig. 1 illustrates a hollow steel punchingmachine embodying my invention. In this Fig. 1,'as well as in all of theother figures of the drawings, the numeral 1 designates the foundationsupporting stand or pedestal of my machine. This pedestal stand may bemade of any suitable material and be of any suitable shape. I preferablyhowever make this stand of structural steel or iron, the frame of whichconsists of angle beams 2, welded together at their top ends at 3, andriveted at their lower ends to projecting foot plates 4, that extend allaround the lower ends of the frame. This stand is in the form of anelongated square fiat topped tapering sided form, and the structuraliron frame is made in this form and is covered on the top and front sideand on its ends with sheet iron 5, which is riveted to the members ofthe frame. The foot plates of this pedestal stand are provided withholes, that are adapted to receive lag screws or bolts, by which it maybe rigidly secured to a plank floor or to a suitable foundation.

, Upon this pedestal stand I mount the several operating "parts of myhollow drill punching machine, which parts in the main comprise the pinoperating cylinders 7 and 8, which are assembled and connected togetherby a yoke 9, and the drill bit vise 11 and its operating cylinder 12.These cylinders are provided with lugs 10 that are arranged to enablethem to be secured to the stand. The connected cylinders 7 and '8 areconnected together by the yoke 9, in axial alinement, and they aresecured to the top of the stand. Each cylinder contains a singlereciprocating piston rod 13 and two independent piston heads 14 and 15,in each cylinder. The piston rod 13 extends through the front cylinder?into the rear cylinder 8. The front cylinder 7 I term the pistonreciprocating cylinder, and it is provided with a rear end integralcylinder head 16, and a removable cylinder head 16 Each of thesecylinder head portions is provided with a stufiing box 16 and a gland17, which is threaded to the stuffing box and a packing follower 18. Thepiston rod '13 extends through both of these stuffing boxes, and thepiston head 14 is threaded to a portionof the piston rod within thecylinder 7 that is threaded to receive it, while the piston head 15 isreciprocally mounted within the cylinder 8, and is secured to a reducedportion of the piston rod by a nut 19. The piston heads are providedwith piston rings 20 and 21. The front end of the piston rod is providedwith a chuck 22, which is arranged to receive and to releasably hold apunching pin 23. This punching pin 28 is a round slightly tapering pinof steel or other suitable metal, the outer end of which is pointed,while the inner terminal end of this punching pin is preferably providedwith a flat enlarged head portion 23". The chuck may be of any suitableconstruction to properly grip and hold the pin.

I preferably however have constructed a chuck having a hollow sleevebodyportion 24, that is fitted snugly but removably to a reducedshouldered portion at the adjacent terminal end of the piston rod, whichis squared off fiat. This body portion of the chuck is secured to itpreferably by a tapering pin 25, that is extended at right anglesthroughthe body of the chuck and the end of the piston rod. The innerperipheral wall of the outer end portion of this body 'portion isthreaded and a plug cap 26 is threaded into it. This cap 26 has an axialaperture 27 through which the tapering end of the punching pin isinserted from the inner side of the cap, which has to be removedfromjthe body of the chuck in order to place the pin through theaperture in its end.

The inside flat surface of the head 23 of the punching pin, lies flatagainst the end of the plug cap, and this plug cap is so arrangedrelatively to the body of the chuck and the terminal end of the pistonrod that when it is screwed into the body of the chuck it moves andclamps the outside flat surface of the head of the punching pin againstthe flat square end of the piston rod, which acts as a rigid abutmentfor it and allows the piston rod to force the punching pin into thehollow drill steel through the medium of the expansive fluid in thepiston reciprocating cylinder 7 acting on the pisten 14.

My invention however contemplates broadly the use of any form or shapeand of any kind of a punching pin and of a chuck for holding the samethat can be properly attached to the end of the piston rod. The cylinder7 is preferably connected to and its piston is reciprocated by a supplyof com pressed air, although any other suitable expansive fluid may beused if desired. The opposite ends of this cylinder are provided withports 28 and to which one end of air supply pipes are connected at ashort distance above the cylinder to a four-way valve 30, that isarranged between them,

from which a pipe81 extends down to the stand and connects to a generalair supply pipe 32 that extends along the side of the stand and issecured to it and that also furnishes a supply of air to the viseoperating cylinder 12. This general air supplying pipe is provided witha three-way valve 33, that is connected bya pipe 34- to a supply ofcompressed air of suitable pressure to operate the pistons of thecylinders 7 and 12. The four-way valve is operated by a hand lever 35 toadmit air to the opposite ends of the cylinder 7 and its piston.

The cylinder 8 is an oil holding piston cushioning cylinder. It isprovided with a stuffing box 36 that surrounds the piston rod 13. Thiscylinder receives a supply of oil through the two-way valve 37, whichoil flows to the opposite ends of the cylinder through the pipes 38 thatextend from the valve 37 to ports in the opposite ends of the cylinder,and which admit oil to first one side of the piston head 15 and then toits opposite side. The pipes 38 constitute a by pass which permits theoil to flow automatically through them from one side of the piston headto its opposite side.

The oil acts to cushion the reciprocating strokes of the air drivenpiston head 14 in the cylinder 7. A suflicient amount of oil is kept inthe cylinder to effectually cushion the strokes of the piston 14. Onlyenough oil is added from time to time to replace the leakage through thestufling box 36. As the punching pin repeatedly enters and enlarges theaxial aperture in the rock cutting bit end of hollow drill steel heatedto a drill sharpening and forging heat it gets very hot and it isnecessary that some means be employed to cool it and to keep it at apractically operating temperature.

My invention contemplates any suitable means for accomplishing thisobject. I preferably however, employ a fluid for cooling the pin andfind by experience that a jet of compressed air discharged continuouslyon the pin when it is being used in enlarging the axial aperture inheated hollow drill steel makes an effectual cooling medium, and Iconvey a stream of air to and discharge it directly against the pin fromthe general air supply pipe 32 through a small pipe 39 that is connectedat one end to the supply pipe and its opposite end is bent to dischargethe air directly against the heated punching pin.

This pipe is provided with a valve lO and the air discharging end of thepipe is provided with a flattened nozzle 41. The drill steel holdingvise is mounted on the front outer end portion of the stand, in front ofthe punching pin and at a distance from it to allow the end of the drillsteel that is clamped just back of the heated end to be within thereciprocal stroke of the punching pin. This vise consists of two plates42 that are each provided with feet portions 43 which are bolted to thetop of the stand 1. These vertical plates T2 are placed at a distanceapart necessary to receive between them an interchangeable but fixedblock shaped jaw a l, which is bolted and clamped rigidly between themby bolts i5 'that'extend through both plates and the jaw and clamp allthree together.

The two plates are provided with recesses 4E6 that are arranged inalinement with the longitudinal axis of the punching pin 23 and itsactuating piston let. These recesses are large enough to receive and toadmit to the largest sizes of drill steel used in drilling engines, andthe front edge of the fixed jaw extends close to the vertical plane ofthe axial center of the puncl'iing pin, and at its center it is providedwith a recess of semicircular form to fit the cross section of eitherround, hexagonal or other forms of tool steel. A half round recess isshown as hollow round steel is preferably used.

I also place between the vertical plates a2 a movable jaw i7 which ismounted. to swing up and down to and from the fixed i This swinging jawfits loosely between the plates and is pivoted to them by a pin tS thatextends tl'irough them and the jaw.

This jaw has a drill steel engaging recess as that is of curved form andthat is positioned opposite to the recess in the fixed jaw, and whichmay be made to fit any form of cross section of drill steel, but whichis illustrated adapted to clamp round tool steel in the recess of thefixed jaw. This movably mounted swinging jaw has'a rearwardly extendingshank portion that exthe side of the stand and a supplv of air is led toit from the three-way valve 33 in the general supply pipe 32 through apipe 53 that is connected at one end to the valve and at its oppositeend is connected to the bottom of the cylinder. The piston rod 52extends into the cylinder through a gland ring at that is threaded tothe cylinder head. The inner end of the piston rod 52 is provided with apiston head 55 that is reciprocally mounted loosely enough to drop quitequickly by its weight against the air below it, which acts to cushionit. The air is admitted to the bottom of the cylinder, while the upperend of the cylinder is open to the atmosphere, through a vent pipe 56that is threaded to the cylinder head, and that prevents any air beingcompressed above the piston head to interfere with its exerting its fullupward pressure against the swinging jaw when air is applied to itsunder side. I

The air entering the bottom of the cylinder forces the piston head androd and the link upward, and closes the swinging jaw against the fixedjaw or against a drill steel if one is placed in the recess, of thefixed jaw, with great pressure. I The fixed block jaw is made thickenough so that its steel supporting recess is long enough to act as afirm and steady support for the drills, and they are firmly and tightlygripped in this air power vise and are held in true axial alinement withthe longitudinal axis of the punching pin and its piston rod.

The operation of my hollow steel punching machine is as follows:

The ends of the hollow drills to be re sharpened or of the new lengthsor bars of hollow steel on one end of which a rock cutting bit is to beformed are heated in a suitable forge to a suitable forging heat. Thenan operator takes one in one hand and places it in the recess of thefixed jaw with its heated end projecting into the path of the operativestroke of the punching pin; and

at the same time that he places a steel in the fixed aw, he opens thethree-way valve 33 to admit compressed air into the cylinder 12 whichinstantly closes the swinging jaw e7 against the drill and clamps itrigidly against the fixed jaw, in which position the center of its axialaperture is in alinement with the longitudinal axis of the punching pinand its actuating piston.

The operator having clamped a steel in the vise, leaves the valve openso that the air pressure exerts a constant pressure on the piston headof the vise cylinder and holds the steel gripped continuously in thevise. The operator then opens the fourway valve 30 to admit compressedair into the rear end of the cylinder, which acting on the piston head14 moves the piston rod forward in the cylinder and forces the punchingpin by a single quite quick forward stroke into the aperture in theheated end of the steel and expands and enlarges it to a tapering holethat is preferably sevensixteenths of an inch. in diameter at itslargest end, but that can be made a trifle larger or smaller if desired,as the pin is a taper pin. v V

The operator then reverses the valve 30 to shut off the air to the rearof the piston 14: in the cylinder, and admit it to its front end, whichmoves it to the rear end of the cylinder, and withdraws the punching pinfrom thesteel, leaving a clean round smooth enlarged tapering hole inthe center of its heated end. The operator now instantly releases thesteel from the vise by moving the three-way valve to shut off air fromthe lower end of the piston head. This al lows the piston head to dropin the cylinder quite quickly, and as it does so, it forces the air outand back through the pipe 53 and out of the open aperture in thethree-way valve to the atmosphere.

The operator the instant the steel is released, places the steel in adrill sharpening machine, and it is sharpened with the same heat. Theentire operation of gripping a steel, enlarging its aperture in its bit,and releasing it, is accomplished in a few seconds. I

A current of cool air is kept constantly discharging against the pin,from the air pipe which keeps it cool enough to be used as fast as theheated drills are submitted to its action.

My invention provides a quick and positively operating machine for soenlarging the rock cutting bit ends ofv hollow drills that much moreaccurately and true rock cutting bits and lips are formed on the one sof drill steel, inaddition to the saving of about fifty per cent. of thetime required in forming and resharpening drills, which is an economicfeature of considerable value in mines that have a large number ofdrills to keep sharpened.

.Having described my invention, what I claim as new and desire to secureby Letters Patent, is: i

1. A machine for enlarging the axial aperture in the rock drilling endsof hollow drill steel, comprising a fluid actuated piston operatingdrill steel holding vise, a fluid actuated reciprocating pin arrangedand adapted to enter and enlarge said axial aperture, means including achuck carrying pis ton rod arranged to removably and renewably supportsaid pin, cushioning means operating on said pistons for reciprocallyoperating said pin, a piston head secured to the opposite ends of saidpiston rod, a cylinder surrounding each piston, and means includingfluid passageways in said cylinders whereby said pistons operate andcushion the reciprocal movements of said piston rod and pin.

2. In a hollow steel punching machine, the combination with thesupporting stand and the punching pin actuating and cushion ingcylinders and their operative mechanism, with the hello-w steel grippingvise comprising the side plates and the fixed and the movable jaw, thecompressed air cylinder and its piston, the link connecting said movablejaw to said piston, and means including a three-way valve for providingsaid cylinder with a supply of compressed air, said cylinder beingarranged to force said movable jaw to grip and rigidly hold a drillsteel against said fixed jaw with a constant pressure for a period oftime.

3. In a hollow steel punching machine, the combination of the supportingstand, the drill steel gripping vise secured thereon and the fluidactuated cylinder mounted on said stand, and arranged to open and closesaid vise to grip and release heated hollow drill steel, with a punchingpin reciprocally mounted to enter the axial aperture of the rockdrilling end of heated drill steel clamped in said vise, the connectedcylinders secured on said stand, the piston rod extending through onecylinder into the other, the chuck on the outer end of said piston rodarranged to releasably hold said punching pin, the piston head on saidpiston rod in each cylinder, and means including the operative pipes andvalves connected to said cylinders for reciprocating and cushioning thereciprocal movements of said piston and punching pin.

4:. In a machine of the character described, a supporting stand, a pairof cylinders in alinement secured on said stand, a yoke connecting saidcylinders together at a short distance apart, a piston rod extendingentirely through one cylinder and into the other cylinder, a piston headin each cylinder on said piston rod, a chuck on the outer end of saidpiston rod, a punching steel pin releasably secured and held by saidchuck, a drill steel holding vise secured in front of said pin on saidsupporting stand, said vise having a fixed and a movable drill steelgripping jaw, a compressed air actuated cylinder and piston arranged tooper ate said movable jaw, means including a valve controlled compressedair supply pipe arranged to supply said chuck piston and pin actuatingcylinder and said 'movable jaw cylinder with a supply of compressed air,and means including a by-pass piping system connected to the chuck andpin actuating cylinder.

5. In a machine of the character described, the combination of asupporting stand comprising a frame of structural metal, a pair ofcylinders connected in alinement by a yoke and secured to the top ofsaid stand, one cylinder of which is a piston reciprocating cylinder andthe other is a piston cushioning cylinder, a piston rod extendingreciprocally through said piston reciprocating cylinder into the pistoncushioning cylinder, said piston rod having a piston head on it in eachcylinder and a chuck on its outer end, said chuck comprising a sleeveremovably pinned to the end of said piston, a plug cap threaded into theend of said sleeve, with a tapering hollow steel enlarging pin arrangedto be removably held by said chuck, said pin comprising a long taperingbody portion and a head portion, said plug cap being provided with anaxial aperture through which the body of said pin projects, and the headof said pin being ar ranged to fit loosely in said sleeve and be clampedby said plug cap against the end of said piston rod, ports in theopposite end of said chuck and pin actuating cylinder pipes connected atone end to said ports and connected to the opposite ends of a four-wayvalve, means including a pipe connected to said four-way valve forconnecting said cylinder to a suitable supply of compressed air, a pipeconnected to the opposite ends of said piston cushioning cylinder, avalve connected to the opposite ends of said pipes, and means includingsaid valve for admitting a supply of oil to said cylinder and forconfining it therein to cause it to circulate from one side of saidpiston to the other through said pipes to cushion the reciprocatingstrokes of said piston head, the piston rod and the pin, and meansincluding a power operated drill steel gripping vise secured on saidsupporting stand and arranged togrip and hold heated hollow drill steelwith its axial aperture in alinement and in operative enlarging relationto said pin.

6. In a machine of the character described, the combination of thesupporting stand, the pair of cylinders secured to the top of said standconnected in alinement and separated, one of which is a pistonreciprocating air driven cylinder and the other the piston oilcushioning cylinder, means including a four-way valve for operativelyreciprocating the piston in said piston reciprocating cylinder, andmeans including a valve for providing the piston cushioning cylinderwith oil and cushioning the reciprocating strokes of said piston, achuck on the outer end of said piston and a hollow steel axial apertureenlarging pin removably secured in said chuck, with a hollow steelgripping vise and an air power operating cylinder and piston secured onsaid stand and arranged to open and close said vise, said visecomprising a pair of parallelly arranged plates extending across the topof said stand at right angles to the longitudinal axis of said pin andpiston rod, and the pistons reciprocating and cushioning cylinders saidplates being each provided with a fixed jaw removably secured betweensaid plates, said fixed jaw being provided with a drill steel receivingrecess arranged to cen ter the axial aperture of hollow steel centrallyin alinement with the longitudinal axis of said pin, and adapted to fitsteel of any form of cross section, a swinging jaw pivoted between saidplates, a link pivotally secured at one end to said swinging jaw andpivotally connected at its opposite end to one end of a piston rod, theopposite end of which extends reciprocally into a cylinder and isprovided with a piston head, a cylinder adapted to receive said pistonhead and rod reciprocally, an axial aperture in the top of said cylinderopen to the atmosphere, and means including a three-way valve and pipingconnected to the bottom of said cylinder and arranged to be connected toa supply of compressed air for operating said piston to move saidswinging jaw to grip and hold a heated drill steel against said fixedjaw and in operative axial aperture enlarging relation to said pin.

In testimony whereof I ailix my signature in presence of two witnesses.

THOMAS DAVIES Witnesses:

CLARENCE Vro'ron HorKiNs, SINCLAIR THOMSON Lonr'rrr.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

